The present disclosure relates to display technologies, in particular, projection-type display devices.
Light projection is used to display images on large surfaces, such as large computer displays or television screens. In a front projection system, an image beam is projected from an image source onto a screen, which reflects the light toward a viewer positioned in front of the screen. In rear projection systems, the image beam is projected onto the rear side of a screen and transmitted toward a viewer located in front of the screen.
System size is an important consideration for projection-type display device. For rear projection display applications, a small footprint is usually desirable because the project-type display is often compared to the thin flat-panel displays based on liquid crystal, plasma, and organic light emitting diode technologies.
The light source for a project-type display can be produced by a spatial light modulator (SLM) based on a micro mirror array. In general, a micro mirror array can include an array of cells, each of which includes a mirror plate that can be tilted about an axis and, furthermore, circuitry for generating electrostatic forces that can tilt the mirror plate. In a digital mode of operation, for example, there are two positions at which the mirror plate can be tilted. In an “on” position or state, the micro mirror reflects incident light to form an image pixel in an image display. In an “off” position or state, the micro mirror directs incident light away from the image display.